posted 09-26-1999 09:42 AM         

Can anyone confirm the same yields as Sumerian.

Which brings me to another point. In Rhodiums MeAm FAQ there is a vacuum reflux method using Formaldehyde and Ammonium Chloride, interestingly, the yield of MeAm was ONLY 38%.....which is less than the equivalent open air method !! Strange thought prickleberry.

So....whats the big deal with vacuum refluxing ?? What does it do that supposedly boosts the yields?? Lets look at this reaction more closely.

VACUUM REFLUXING EFFECTS
- It pulls CO2 out of the reaction. CO2 shouldn't do any harm. CO2 comes from CHOOH (formic acid), and this helps the reaction.
- It makes the reaction bubble (reflux) at a lower temp, I can't see how this would help.
- It possibly pulls formaldehyde out of solution....this can't be good, we put it there to react, not to evaporate.
- Less atmospheric oxygen is there to react, is this important?? I doubt, otherwise we would be be refluxing under an inert atmosphere.

Prickleberry now wonders if the reaction would work better in a sealed container, like a pipe bomb.

SUMMARY
Low temps help the "Sumerian method" by reducing side reactions, but is vacuum refluxing really necessary and why ??

posted 09-26-1999 03:33 PM         

Maybe if you write some details we can see where it went wrong. What are your yields with the normal non vac method? Do you remove any AmCl prior to reacting? How long is hydrolosis before reacting?

Use of vacuum allows the reaction to occur at a lower temp with less sensitivity towards producing either diMeAmine or MeAmine. CO2 evolution (evidence of reacting) and refuxing are both attained at this lower temp. It doesn't pull formaldehyde out of solution, as it is returned by the vertical condenser to the reaction. A pipe bomb would build pressure, and make the reaction proceed at a [b]higher[/temp], which would not be good.

There is no 'vs' really. The Sumerian vac method is simpler, faster, higher yielding, and has a much easier workup, IMO.

posted 09-27-1999 04:47 PM         

Icepick: Can you confirm ~1.2kg from ~800 hex with the non-vac? How many flushes of AmCl precip out?

posted 09-27-1999 10:37 PM         

Equarius/Bitch-Slap/neutspellc.....whatever, Bitch-slap's a good name, maybe you can get back to equarius if you send Rhodium an apology, and tell him you won't whine.

posted 09-28-1999 12:34 AM         

Anyhow I'm tired of this crap, and have done all I can to avoid this. All I've ever wanted to do was chemistry here. I'm no longer a bee..

goodbye all

posted 09-28-1999 10:35 AM         

Tell you what! I'll leave your girlish Canadian-ass alone as long as you stick to the chem and refrain from all future American-bashing, bee-bashing, and whining in general... How dat?

posted 10-15-1999 12:20 AM         

pulling CO2 out of the reaction is a good thing imho due to that french guy's principle, you know, a system subjected to stress (blah blah)....

when formaldehyde reacts with ammonia, an imine is formed. this imine is reduced by another molecule of formaldehyde producing (among other things) CO2. pulling off CO2 actually drives this particular reaction towards products, which should increase yields.

lower boiling temperature, means less energy for the reaction, possibly making the imines form faster. possibly not.

as for pulling formaldehyde out of solution... i doubt it. two reasons: first, formaldehyde in water forms a gem-diol (about 95% gem-diol to 5% aldehyde) which is extremely water soluble, second this high solubility forces the CO2 which has less ability to react favorably when solvated in water to bubble out preferentially to the formaldehyde. this is kind of like what happens when you pour sugar packets into a freshly opened can of cocaine-cola.

posted 01-23-2000 09:07 PM         

Anyways aside from the basic knowledge has anything new been offered nope!

Well how about electrochemical???? this would be simple I think???

Lastly ya can react the ammonia with the methycloride to yield the methyamine wouldent this be easir???
nh2/nh3/nh4////chcl/chclcl/chclclcl resulting in the formation of the desired salt this would eb a bit more simple to appreciate at a profit to manny??? so ya have the basic amine shit nh4-o or call it nh3-oh I could care less there are easyer ways but this would essentially be the first base......so if we loss a water ya would get a half yield of water and nh2
NH2 is what we want>>>>>>>>>..........to compenstae for this reaction we add the desired stuff to combine to the ammonia stuff to yied methyamine.......we want the methy to arrive for carbocation un harmed.....

alot an excess of ammonia insures methyamine less ammonia affords on ocasion quat compounds....another mater......

so ch2cl-chclcl I think this is the best way to descibe this shit......of course we could go with the plain stuff less active though for practality I include it ......chclclcl this will not work as well though......

Anyways useing the simplifed stuff......

ch2cl-chclcl it will become this if ya heat it up.......without much effort as long as ya exclude light....DARKROOM.......so...

ch2cl and or the other stuff need be considered however if the stuff basses out it will humm nedd be seperated up the amine will fall into the water as the base and at super bassing the amine will go into the nonpolar following proally the na component this most likely be afforded by heating and adding salt to activate the reaction.....

so nh3oh upon basification ya are adding naoh to this stuff to get a gass of nh4 see that the change relates to water forming from the the previous stuff a gass would have been into water water is a base like stuff the ammine would loose a hydrogen trying to buffer it up the water and at that same time assume a base like structure wierd hugh???

Anyways the ammine an acid at this nutral point in a weak base it form up with wwater and becomes nh3oh ya never know for shure its just a theory afterall.....ya could just as well articulate it as a nh4oh it dont matter when ya add the base of course it aint a naoh that dont really exist it that is in water it dont it does explain the action of it in water but it aint that way....the best way is to think of it as nao......see nao is added to the water and this extracts active hydrogens from the water that are making it more acidic than it would be without this addation........, after a bunch of the water freak hydrogen ha been disolved the na might it has a saturation point of course like a pressure potential and the sodium will of course some of it will go into the nonpolar layer, there it starts doing the same thing as in water,, however it is different it has to bring a radical kida thing with it to accomidate itself thats why the explination seems to work......see the amine gets the sodium....hydrogen is supposably freed up bullshit hydrogen is had by the nah and being how the saturation of the hydroxide is alleardy at a point thus the ammine is towed into the np layer where the ummm yep clorine is lost into the water it the catalyst the clorine was opon the amine previously na cl is umm yep its salting out look for it....sinks.....anyways the ammine towed up the hydrogen is not frreed from the dissociating acid it is trapped between the ammine and the sodium and this attaches to the nonpolar oxygen should any be present....his is proally why it prefers the doubly attached oxygen nonpolar solvents such that in fact acetone is an ideal solvent medium for nonpolar bonding in.....maybe in fact too good in this case the satiurated shit might be washed away in a different process,,, to get the amine out of the nonpolar layer or an alchol layer humm accetone aint an alchol....ch3-c(o)-ch3

So hummm anyways shit ahappems hummm

So the nh3oh/h thats a base in water.......
The shit gasses out due to that it must be forced out due that it aint soluable in that something going on here need be investigated it why the typical process fails I think......thus ya add salt add salt this works the raional sucks though.......

so anyways asside the gass comes up and into the nonpolar solution or whatever might be there in this case we are ussing whatever works.......a salt water and nonpolar solution two phase I think who cares???? salt up shit is the ammonia clorides shit and the nonpolar shit thats the good stuff the gasses are there as well as that we can simplify shit by just ussing meoh anyone that cannot make methanol should get a brain or a repot card notifivcation.......

so the hn4 is in going into nonpolar or assisted by alchol,,great methyalchol might work splendidly as well as acedic acid however these may differ due to paticuliars of interest considering pressure and tempature the basic stuff of course as elllas ambient light......so ya would have a whole bunch of shit going on I would hope this would be the worst case semnerio considering the trav ids difficult........

Humm this is dam well its dissordered cause this is where ya strat such an investigatioin have at least two know products available a water like stuff, an alchol like stuff and likely an combinational stuff like the methyamine and amonia clkoride hopefully ya could at least get 50/50 w/o much brain work......however if ya were to adjust just one variable this ration would change drastically in favor of one sole product and giving that essential info away would be like fueling a firre man......there be a bunch of different wways to do this to be shure the most difficult and hazardous has been presented........